Let-off



Mar. 5, 1929. A. s. HuTcHlNs LET-OFF Filed June 8, 1.928

2 Sheets-Sheet J.

Mar. 5, 1929.

A. s. Huffcmrs LET-OFF 2 Sheets-Sheet 2 .Filed June 8, 1928 .2*4 j Z 23 Patented Mar. 5, 1929.

:PATENT fr 1,103,884 orrice.

ALLAN s, HUTcnINsl-orwononsrnm-nssscnusms, Assn-mon ro (morirme n xNoWLEs LooMvWoRKs, Yor woncns'rnn; MASSACHUSETTS, A consensuel( or MASSACHUSETTS. i

Application led June 8,

This invention relates to let-offs for looms and it is the general object of the invention to provide a Weighted let-off operating to utilize the Weight of the Warp beam to tension the Warp threads.

One ofthe best Ways to secure even tension on Warp threads so as to insure uniformv clothfis tosubject the warp threads to the pressure of a -WeightYVWh-ich is moved l'o as the Warp thread is used up. Thismethod is found to be very satisfactory 'in the weaving of such fabrics as hat bands vWhere unilformity of cloth is absolutely essential. It is anY important object of my present inven tion to employ the general principle of a weight by supporting the warp-beam partly by the'warpfthreads andpartlyon a pairof endless chains, feedingthe chains so as to vlower the Warpfbeam periodically as the -20 same Areaches a -predetermined elevation. In this'way the Warp threads Awill be constantly subjected to the Weight of thebeam to insure uniformity of tension. V During Weaving the Weight ofthe Warp 25 beam decreases and in order to compensate for this I contemplate the use of a counterweight which maybe varied, thef tension on therwarp being substantiallyrthe di'erence z between the Weight 'of the beam and the 0 pressure excrtedby the counterweight, the latterbeing lessened' as vveavingjr continues so Ythat lthe difference between these two pressures will remain constant to insure uniforniV tension in the warp thread;

It is a further object o my present invention to provide means for manually lowcrinr the Warpvv beam at the time of a pickout.

jVVith these and other objects in view which will appear as the description proceeds, my invention resides in the`combination and arrangement of parts hereinafter described'and set forth in the claims.

In the accompanying drawings wherein a convenient embodiment ofv my invention is set forth, Y

ingr the control shield in shielding and non` shielding positions, respectively. *Y

.fixing particularly to Figs. 1 andf2,I

.have shownthe loom frame =1O Weights 6 1 may behang onthe rod S28-and v upper partof Aone of the brackets 15, Chat v herein.

1 is a side elevation of a loom made thev gether.

'worm and worm gear pr rotating thesprocketg 24 and ,morder to: H110 LET-01T.

mechanism 11 to receive cloth C.v he ywarp threads W extend fromv the cloth rearwardly through harness mechanism not shown and may extend over a guide roll l12. From. the no roll the Warp extends to a beam 13 having a shaft-14. Located at each side. of the -loom Visa bracketol which has anupwardly openingk vertically extending slot 16 through whichrthe corresponding end of the shaftfl4 extends. Each bracket 15 is provided with a support 17 Ywhich is secured to the bracket for vertical' ad'ustment by means of afoot V178. Each foot as a vertical slot 19 through which pass bolts 20 b means of which the support 1'( may be he d in adjusted vertical position.` Y Y ,f Each .bracket 15 has van upwardly projecting rear horn v2,1 anda second 0r f @fward horn 22. Y Extending between horns 22 is a shaft 23;to each end of which is secured a' sprocketV 24 so that said sprockets and shaftturntogether. Eschborn 21 is provided with a stud 25 on which is freely rotatable Va sprocket 26 Substantially rn Valignment `with the corresponding sprocket.

The lowerendof each bracket `15 is 'pto- -vided with anr upwardly extendingwbut downwardly openingslot 21 through which kextends a'rod 28.to each end-.of which is secured a sprocket 29. A sprocket is Secured to each endjof the Warp beam Shaft 14 and all of the sprockets on one side of the loom will lbe substantially in theamevertical plane. At each side of the looxnis a chain'which meshes with the SpiOdSBt-s at'y that side of the'floom, as shown ig..-1l`

manipulatedv in fa manner Ato be descrhod`- hereinafter. Y A horizontal crosslslaaft 327 is rotatable fthmvughv lbearings 33. and A34 ycarried ,by the located at theright ofY Fig. 2 as shown Tothe rear end of said shaftzis -a wormv35 which meshes with wenn gear 36 secured to the shaft. Saidworm, worm gearand sprockets 24 ,together with shaft 23,' therefore, are seen tormoyedo- A hand wheel 36 atthe front end ofathe shaft B21-*maybe 4provided riif'desired. The Y oevide means. for

nos 'i complish this result under power I provide a Vconstant rotating shaft 37 to which is secureda cam 38 which acts on a cam leverl bearing 34 under normal conditions Vso thatl said :bearing prevents movement of the worm to 'the right Aas viewed in Fig. 1 to prevent rotation'V of the sprocket and shaft f The feeding of the ratchet is under control ofthe warp bemin-the control being ef- "f ected by means of a shield 45 mounted on the upper'end ofa vertically adjustable rod g46. Said indie-operatively connected to a control lever 47 pivoted as at 43 to a portion 'of the support 17 to be movable vertically with thelatter. The rearwardly eX- tending-arm `49 of the lever 47 extends over the shaft 14as set forth'in Figs. 1V and 2.`

Ifdesired, the weight of the empty beam maybe regulated to give .the desired tension on the warp threads and weights 31 may be 'added-to the rod- 2S tov an extentsuicient to counterbalance the weight. of the yarn on the warp beam. Under these conditions and with `the warp beam'in a relatively low Y. position, the shieldj 45 willY be raised to the position-'shown in Fig. 3 so' that the worm 351w1ill vact'to '.hold the sprockets 24 infiired position. The vertical portion .or llimbrOY of the chain E will therefore be held against `downward movement and as the warp isv used up 'in making 'cloth the warp beam-13 will turnaround its axis in a clockwise` direction, causing the sprocket 30 toclimb up saidportion 50YV by slowrdegrees. As the clockwise direction about the stud 48. This l ratchet will-'be rotated in a counter-clock? -wisedirection as.l viewed in Fig. 2; and thev worm will befgiyenfsuch a movement asY will. result in the lowering 'of Vthe shieldr45 tothe position shown in Fig. 4 where it will fbefseen that the pawl 42 is in. positionf-to Y engagethc teeth of the ratchet 43.

' will turn `the sprocket 24m a counter-clockwise direction as viewed iii' Fig. 1 to lower the limb or portion 5() ofthe chain E This downward movement of portion 50 is accompanied by acorresponding descent of the Vbeam and attendant raising of the shaft j Q S'and the Yweights carried therebg'nt'wr'lhe varm 49 is weighted to followthe shaft-,14

" Y andthe shiel'df45"will be moved upwardly `65 to lassume thefpositionshown in Fig. 3 to v prevent incassa further positive feeding of the chain. f

The opei'ation just described is repeated throughout the running'of theploom,` the warp beam moving up.graduallyy and being fed back positively, the warp 'berno' subject- ;ed to the vtension Vdue only to the lifting of the beam. Because of the fact that the chains arecontinuous theoperation as described will continue irrespective of the length of the warp wound on the beam rela tively to the length of the chain. Y

As'previously stated the tension on the vwarp depends upon the difference between the weight of the beam and the counterweights 31 and in order to keep this difference constant l arrangeto remove certain of the weights 31 fromtiine to time as the diameter of thewarp beam decreases.

At'the-ti'me` of pi'ckout it is necessary to let the'fell of tlief'cloth back and this may be accomplished by rotation ofthe hand wheel 3G. lf the warp `beam be in a relatively liigh'position' tlietime a pickout is madetliebeamv will fall of its o\vnweiglit to'take up cloth.Y which is let back by 'loosen ing the takeiip 11. If it should sofhappen, however. that the shaft 14 were'resting on the support 17 so that' further.downward motion of thebeam'to take up slack is impossiblethe hand wheel 36 may be rotated in such a way as to lift tlie'sfection 5G of Vthe chain, causing rotation of the beam in a directionto take uptheslack warp. This will be `possible because of kthe fact that-'under these conditions thegshield vwill be vup due to thelowered'position ofthe beam and the pawl will not act to prevent retrograde movement-,of the ratchet 43.

lF rom the foregoing it will be seen that l have provided a siinple-let-off wherein lthe tension. on the warp threads is Vdue solely to a weight which raised as the warp consumed, the weight; being periodically lowered. It will further beiseen that by the usc of he-endless chain l am ablelto combine withA the weight of the beam an element having a variable weight so that thernet weight .which is broughtto bear upon the warp kthreads may befkeptconstant as tho-diamveter of the beam decreases. I lt will further rAsp-'the vcam 38. lifts kthe lever 39 the be seen that the. worm and wormV gearA operate to hold one of the fsil'irockets and there#A Vto make a; pickoutthe chain may be moved a reverse direction if necessary to place the warpbeam VVin the proper posit-ion, the locationof theishield permitting suchV reverse motion of the parts.

"Having thus described. my invention it ienY vwill be seen that changes and modifications may be made therein by'those skilled inthe art Wit-hout depart-ing from Vthe -spiritV and scope of the invention and I do not Wish to be limited to the details herein disclosed, but what I claim is: s Y 1. In a let-off for looms, a Warp beam,

means to guide the'vvarp beam in a vertical,

the'using up of the warp, and means de pendent upon the position of the beam Vto feed said chain in a direction to lower the` beam when the latter reaches a predetermined elevation.. y

3. YIn a let-off' for looms, a Warp beam mounted for motion in a direction to have a verticalY component, av sprocket movable ,about affixed axis, an endless chain meshving with the sprocket, a" second sprocket secured to and rotating with the beam and meshing with the chain, means to hold the` irst sprocket normally Ystationary to prevent movement ofthe chain so as to cause the beam to move upwardly along the chain as the beam rotates incident to paying off warp during the Weaving'operation, and means 'controlled bytheposition of the Warp beam by and tensioning thewarp threads, means to cause said beam to be elevated'thnough the rotary motion of bhe beam incidentto the paying-off ofwarp from the beam,and

means acting on the beam to lower thelatter `70 when the beam has attained 'a elevation.

6. In a let-off for a loom, a warp beam guided 'for motion vin a direction havingv a predetermined vertical component, -an endless chain, a `'f5 sprocket movable about a` fixed axis meshing with the chain, asecond sprocket secured lto and rotating with the beamand meshing with the chain, means to prevent rotation of the first sprocket under knormal 4"fic condi-tions so `that as the beam rotates dale to ypayin -o warp the second'spnocketand beam wi l Vclimb upwardly along the chain and variable means to weight the chain;

7. In a let-of for a loom, a warp -beam's i guided for motion-in a directionha-ving a vertical component, an endless chain, a sprocket movable about a fixed axis meshing with the chain, asecond @rocket secured to and rotating with the beam andi mesh-'50 ing with the chain, means to prevent rotation of the first sprocket under normal coni dtions so that, as thcbeam rotates due to paying off warp the second sprocket and,` beam VWill climb upwardly along the chain`-95 and variable means to set'the' chain, and means to feed the chain l in a direction .to effect lowering of the beam after the latter has attained a, predetermined/elevation.

8. Inra let-off vfor 1coms,a warp beamim i guided for movement in a directionv .having a vertical component, a sprocket rotatable about a fixed axis, a second sprocket mowing with 'and secured to the beam, a third guide in to `rotate the first named sprocket to give the chain a feeding movement in a direction toflowcr the beam.V f, f 4. In a let-off for looms, a Warp beam guidedV for movement in a` direction having a vertical component, a sprocket rotatable sprocket, an endless chain extendinfr over r`105 the ,first and third sprockets and u Vr the second sprocket, and ymeans eratively con# nected to the lower part ooiP the chain -to weight the latter, the second sprocket and beam climbing up 'a portionof the lclriain 11o about al fixed axis, a second V'sprocket sccured to and rotatableWit-lrthe beam, VaV

chain connecting and vmeshing `with, lsaid sprockets, means associated Awith the first named sprocket to holdthe chainstationary under normal conditions, rotary movement of! the beam incident to Vpaying off warp during the Weaving operation causing the second named sprockctfto move upwardlyl along the chain to'raise the beam, arcgu-Y larly moving feeding device, and means con--V troiled by the vertical positionoi the beam to connect said Vfeeding, VdeviceY to the first named sprocket when theV beam reaches af due to therotaryvmovement-of the beam incident to paying o warp,`means. the, beam to lo-werthe latter Vwhen the beam has attainedia' predeterminedY elevation, and means acting normally toiprevent downward 115" movement of that portion ofthe chain up which the second sprocket moves.y v ,-1

-9; In a let-'off for" looms, ai warp be Iguided for` movement in "a direction having( a vertical component, a sprocket rotatable' 1 20 about a fixed axis,a second sprocket moving with and secured `to the beam, a third guide s' rocket, -anV endless chain extending over t e first and third sprockets andnnder the ce predetermined elevation to turn said sprock- Aet andmove the chain in a direction to Vlower the beam.

' ,-5. In a let-off for aloom, a beam guided for movement in a direction. to have'a verticalcomponent, said beam being supported second sprocket, and means operatively con- 125- nected to thechain' to-weight thelattenfthe second sprocket and beam .climbing up'fa portion 'of the chain due tothe r .moi-'ef ment of the beam incident to pay'i-ngofi'v K Warp,-meansfacting 'on-tire beam' to-{lcweritbelc Y4` n Y' 1,703,884

beam decreases.

. 10. Ina let-o5 for looms,.a;w'arpVY beam guided for movement inV a. Y direction having a vertical component, ya sprocket rotatable about a fixed axis, a-second sprocket moving Y with and secured to the beam, a third Vguide sprocket, an endless chain' extending over lau the first and 'third sprockets and under'tbe second sprocket,and means operatively con- .nectedk to 44the lower part of the; chain Vto weight the latter, the second sprocket` and beam climbing-.upa portion of the chain due tothe rotary movement'or" the beamincident to the paying yoffl of warp,and means acting normally to prevent Y downward movement of thatv portion ofthe chain which the' second sprocket moves, and means to rotate the first Vsprocket-in a direction vto effect lowering of the beam when the latter reaches a predetermined elevation. V

11..In a let-off for looms, a warp beam movable 1in a direction having a vertical component',-a sprocket movable about a fixed axis, a worm gear securedto and moving j withthe'sprocket, a worm meshing with the `worm gear, a second sprocket secured to and rotating with the'v beam, a'chain meshing 'with the sprockets, Ythe worm cooperating with Y the worm gear yto prevent rotary movementot the iirst named sprocket under normal conditions so 'thatasfthe warp beam Y rotates the second sprocket'will climb up the chain due tothe rotary movement off-the beam incident to the payingoff of the warp to raise the bea-m, and meansoperative to; rotate the worm-when the beam reaches a predetermined elevationto cause 'feeding ot the chain in a direction to effect downward movement ofthe. beam. f

12. Ina let-off for looms, a.,warp beam Ymovable in adirection having avertical component, ajsprocket movableA about la .fixed axis, a worm gear secured .toz and moving with-the sprocket,;a worm mcshmgwith the worm'gear, a second sprocket secured to and rotating with the beam, a Vchain meshing with fthe sprockets, the worinV cooperating with'the'worm, gear'to prevent rotary nieve- Y ment of the-first named sprocket under normal conditionsso that as the warp beam rotates'the second sprocket \\f'1ll;climbup.the chain Vduet toV thevv rotary Ymovement ot the Vbeam incident to. the paying off of the warp f lto raise the'beam, andrmeans operativefto rotate the worm when 'the beam reaches. a

V.predetermined elevation` tog-cause feeding of the chain in a direction vto effect downward *movement oftheV beam, said means includ- ;ing a pawl` and' ratchet dependent for their position.

operation on the position ofthe beam and operatively connected tofthe worm.

13.V In a let-off-for looms, a. warp beam movable inl a direction having a vertical component, a sprocket movable about a fixed axis, a'worm gear-secured to and moving with the sprocket, a worm'meshing with the worm gear, a second sprocket secured to -chaindue to the rotary movement of the.

beam incident to the paying ofi of the warp to raise therbeam', and ineans'operative to rotate lthe worm :when the beam reaches a predetermined elevation to cause Vfeeding of the chain in a direction to effect downward movement ofv the beam, a feedV pawl, av ratchet therefor rotatable with vand rigid with respect to the worm, and a shield operatively positioned bythe beam relatively to the feed pawl and movable to effect co-operation between the ratchet and pawl'when .the beam reaches the said predetermined 11i. In a let-off for a loo1n,a warp beam movable lin Ya direction,v having a vertical component, a sprocket movableV about a fixed axis, a worm gear securedrto and moving with the sprocket, a worm meshingV with the v worm gear,'a second sprocket secured to and mal conditionsfso thatas thel warp beam rotates the second sprocket will .climbV up the chain due to-therotary movemento the beam incident to the paying offof the warp to raise'the beam,-means operative to rotate the worm when' the beam reaches a predetermined elevation to, cause Vfeeding of thev chainl in Va rdirection to eifectdownward V.movementV ofV the beam, and .manual means l5. Inalet-off' for looms, a beam *movableV inea-direction having-a vertical component, a sprocket-movableabout a fixed axis, aV worm gear Asecuredto and moving Vwith the sprocket, afworm meshing with the worm gear, a second-sprocketsecured,to and rotating `with,thebeal'm a cliain meshing .with thek sproekets,y thepworm cooperating Y with the worm` gea-i' rto prevent rotary movement of th e firstv named sprocket under normal conditions so 4that lasthewarpV beam rotates the second., sprocket.- will climb up the chain due, to' the rotary movement'of the beam lincident'to the paying off'rofthe rwarp to raisethe beam, means operative''torotate the worm-when the beam reaches a predetei. .I

Ymimad elevation to.jcausev feeding of. the

`chain in a direction to eii'ect downward movement of the beam, said means including a feed pawl, a ratchet therefor rotatable with and rigid withY respect to the worm, and a shield operatively positioned by the beam relatively to the feed pawl and movable to effect cooperation between the ratchet and pawl when the beam reaches the said predetermined position, and manual means to rotate the worm, said beam when in a position lower than the predetermined elevation moving the shield to prevent engagement of the pawl and ratchet whereby said manual means is independent of the ratchet when the warp beam is in lower position.

16. In a let-off for looms, a warp beam movable in a direction having a vertical component, a rotary member secured to and moving with the beam, a second rotary member movable about a fixed axis, mechanism to gear said rotary means together,

means to hold the second rotary member `normally stationary to hold the mechanism relatively fixed, the first rotary member climbing up the mechanism due to the rotary movement of the beam incident to the `paying oi" of the warp from the beam during the weavingoperatiomand means toef- ALLAN S. HUTCHINS.

afi 

